612 research outputs found

    Genome-Wide Assessment of Stress-Associated Genes in Bifidobacteria

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    Over the last decade, the genomes of several Bifidobacterium strains have been sequenced, delivering valuable insights into their genetic makeup. However, bifidobacterial genomes have not yet been systematically mined for genes associated with stress response functions and their regulation. In this work, a list of 76 genes related to stress response in bifidobacteria was compiled from previous studies. The prevalence of the genes was evaluated among the genome sequences of 171 Bifidobacterium strains. Although genes of the protein quality control and DNA repair systems appeared to be highly conserved, genome-wide in silico screening for consensus sequences of putative regulators suggested that the regulation of these systems differs among phylogenetic groups. Homologs of multiple oxidative stress-associated genes are shared across species, albeit at low sequence similarity. Bee isolates were confirmed to harbor unique genetic features linked to oxygen tolerance. Moreover, most studied Bifidobacterium adolescentis and all Bifidobacterium angulatum strains lacked a set of reactive oxygen species-detoxifying enzymes, which might explain their high sensitivity to oxygen. Furthermore, the presence of some putative transcriptional regulators of stress responses was found to vary across species and strains, indicating that different regulation strategies of stress-associated gene transcription contribute to the diverse stress tolerance. The presented stress response gene profiles of Bifidobacterium strains provide a valuable knowledge base for guiding future studies by enabling hypothesis generation and the identification of key genes for further analyses. IMPORTANCE Bifidobacteria are Gram-positive bacteria that naturally inhabit diverse ecological niches, including the gastrointestinal tract of humans and animals. Strains of the genus Bifidobacterium are widely used as probiotics, since they have been associated with health benefits. In the course of their production and administration, probiotic bifidobacteria are exposed to several stressors that can challenge their survival. The stress tolerance of probiotic bifidobacteria is, therefore, an important selection criterion for their commercial application, since strains must maintain their viability to exert their beneficial health effects. As the ability to cope with stressors varies among Bifidobacterium strains, comprehensive understanding of the underlying stress physiology is required for enabling knowledge-driven strain selection and optimization of industrial-scale production processes

    Biallelic mutation of Protocadherin-21 (PCDH21) causes retinal degeneration in humans

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    PurposeTo describe the clinical findings and mutations in affected members of two families with an autosomal recessive retinal dystrophy associated with mutations in the protocadherin-21 (PCDH21) gene.MethodsA full genome scan of members of two consanguineous families segregating an autosomal recessive retinal dystrophy was performed and regions identical by descent identified. Positional candidate genes were identified and sequenced. All patients had a detailed ophthalmic examination, including electroretinography and retinal imaging.ResultsAffected members of both families showed identical homozygosity for an overlapping region of chromosome 10q. Sequencing of a candidate gene, PCDH21, showed two separate homozygous single-base deletions, c.337delG (p.G113AfsX1) and c.1459delG (p.G487GfsX20), which were not detected in 282 control chromosomes. Affected members of the two families first reported nyctalopia in late teenage years and retained good central vision until their late 30s. No color vision was detected in any proband. The fundus appearance included the later development of characteristic circular patches of pigment epithelial atrophy at the macula and in the peripheral retina.ConclusionsBiallelic mutations in the photoreceptor-specific gene PCDH21 cause recessive retinal degeneration in humans

    Polycyclic Aromatic Hydrocarbons in Some Fishes from the Iraqi Marine Waters

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    This study represent the concentrations of 16 PAHs in 12 of commercial fish species (Euryglossa orientalis , Acanthopagrus araticus , Epinephelus coioides , Chirocentrus dorab , Scomberoidescommersonnianus , Scomberoides lysan , Otolithes ruber , Alepes diedaba , Tenualosa ilisha , Parastromateus niger , Pampus  argentetus , Ablennws hians ) . which were collected from the coastal area of the of Iraqi marine water during 2015. The analysis of Polycyclic Aromatic Hydrocarbons (PAHs) in fish muscles were determined using HPLC to identify the sources of PAHs, The total concentration of PAHs in fishes ranged between (0.432) ng/g dry weight in P. niger and (14.939) ng/g dry weight in  T. ilisha muscles . When we calculated the ratio of (Flouranthene to Pyrene)  and the ration of (Phenanthrene to Anthracene) and ratio of low molecular weight to high molecular weight of PAHs and the ration of Anthracene to (Anthracene + Phenanthrene ) and the ration of Benzo[a]anthracene to (Benzo[a]anthracene+ Chrysene), it is showed that the PAHs origin in fishes were Pyrogenic and Petrogenic . T. ilisha showns high ability to accumulate PAHs compounds  like Fluorene , Anthracene, Acenaphthene and Phenanthrene in muscles compared with other fishes ,  there was different ability of fish to accumulate  the PAHs from surrounded environments  . Keywords: PAHs compounds, HPLC, fishes, Iraqi marine water

    Effects of a brief mindfulness-based intervention on emotional regulation and levels of mindfulness in senior students

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    Mindfulness-based interventions have been applied in diverse populations and achieved mental health benefits. This study examined the effects of a brief mindfulness program for emotional regulation and levels of mindfulness on senior students in Brazil. The intervention consisted of six weekly meetings attended by 30 participants. It is a pre-experimental research, with pre- and post-test comparative and correlation measurements. The preliminary results, which relied on parametrical and non-parametrical tests, revealed a reduction in total emotional regulation difficulties (p = 0.0001; r = − 0.55). Also, there was an increase in the levels of mindfulness in the subtests for both dimensions under evaluation: “Awareness” (p = 0.0001; d = 0.77) and “Acceptance” (p = 0.048; d = 0.37). By associating the amount of meditative practices performed by students with the variables, a significant positive correlation was found with the mindfulness dimension “Awareness” (rP = 0.422; p = 0.020), and there was a significant negative correlation with Difficulties in emotion regulation (rS = − 0.478; p = 0.008) and with its respective subscales “Non-acceptance” (rS = − 0.654; p = 0.0001) and “Clarity” (rS = − 0.463; p = 0.010). In conclusion, the application of a brief mindfulness-based intervention is promising in Brazilian university contexts; moreover, it can bring benefits to students, e.g., an increase in emotion regulation as well as in levels of mindfulness. We suggest that further research should use an experimental design and follow-up.info:eu-repo/semantics/publishedVersio

    Meta-analysis of neural systems underlying placebo analgesia from individual participant fMRI data

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    The brain systems underlying placebo analgesia are insufficiently understood. Here we performed a systematic, participant-level meta-analysis of experimental functional neuroimaging studies of evoked pain under stimulus-intensity-matched placebo and control conditions, encompassing 603 healthy participants from 20 (out of 28 eligible) studies. We find that placebo vs. control treatments induce small, widespread reductions in pain-related activity, particularly in regions belonging to ventral attention (including mid-insula) and somatomotor networks (including posterior insula). Behavioral placebo analgesia correlates with reduced pain-related activity in these networks and the thalamus, habenula, mid-cingulate, and supplementary motor area. Placebo-associated activity increases occur mainly in frontoparietal regions, with high between-study heterogeneity. We conclude that placebo treatments affect pain-related activity in multiple brain areas, which may reflect changes in nociception and/or other affective and decision-making processes surrounding pain. Between-study heterogeneity suggests that placebo analgesia is a multi-faceted phenomenon involving multiple cerebral mechanisms that differ across studies

    SLC25A22 is a novel gene for migrating partial seizures in infancy

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    Objective To identify a genetic cause for migrating partial seizures in infancy (MPSI). Methods We characterized a consanguineous pedigree with MPSI and obtained DNA from affected and unaffected family members. We analyzed single nucleotide polymorphism 500K data to identify regions with evidence of linkage. We performed whole exome sequencing and analyzed homozygous variants in regions of linkage to identify a candidate gene and performed functional studies of the candidate gene SLC25A22. Results In a consanguineous pedigree with 2 individuals with MPSI, we identified 2 regions of linkage, chromosome 4p16.1-p16.3 and chromosome 11p15.4-pter. Using whole exome sequencing, we identified 8 novel homozygous variants in genes in these regions. Only 1 variant, SLC25A22 c.G328C, results in a change of a highly conserved amino acid (p.G110R) and was not present in control samples. SLC25A22 encodes a glutamate transporter with strong expression in the developing brain. We show that the specific G110R mutation, located in a transmembrane domain of the protein, disrupts mitochondrial glutamate transport. Interpretation We have shown that MPSI can be inherited and have identified a novel homozygous mutation in SLC25A22 in the affected individuals. Our data strongly suggest that SLC25A22 is responsible for MPSI, a severe condition with few known etiologies. We have demonstrated that a combination of linkage analysis and whole exome sequencing can be used for disease gene discovery. Finally, as SLC25A22 had been implicated in the distinct syndrome of neonatal epilepsy with suppression bursts on electroencephalogram, we have expanded the phenotypic spectrum associated with SLC25A22. Ann Neurol 2013;74:873-882 © 2013 American Neurological Association
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